SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e43d78911af63d4c897c139e38c0171c05e9e59a552c1fe8987b86fd4722d4f1' 
  AND token = 'cmrK1KdAbfDk+JzuN5AOtQHbwh4gWKqFH4UPQqLj0bI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}